Copper sulfides containing arsenic or antimony are commonly-occurring minerals. Arsenic-containing copper sulfides include sulpharsenites, such as enargite (Cu3AsS4), and sulpharsenates, such as tennantite (Cu12As4S13). Antimony-containing copper sulfides include sulfantimonites, such as famatinite (Cu3SbS4), and sulphantimonates, such as tetrahedrite (Cu12Sb4S13). It is difficult to recover the copper from such minerals. For example, enargite has proven resistant to virtually every leaching process other than high pressure oxidation in autoclaves with oxygen at temperatures exceeding 200° C., which is not an economic process. Mines that process ore in smelters often pay penalties if the ore they ship to the smelter contains enargite, due to high arsenic levels.
It would be desirable to be able to recover copper from mineral concentrates containing copper arsenic sulfosalt and copper antimony sulfosalt minerals by an economically viable, hydrometallurgical process.